@boina yes it has been done before with BOTH p.cam fem and P. Irminia male, and P. irminia fem and P. cambridgei male. Both were successful. My friend still has the offspring from those experiments. They were never sold.
And adult females looked much like this specimen the OP has posted.
Sometimes older irminia fade in coloration and look somewhat similar to the op's T, however, I don't believe that to be the case with this one.. IMO it's a Cambridgei X irminia hybrid.. I definitely wouldn't breed it..
I have owned this girl for almost 6 years and she has looked the same since day one. The photo above was taken shortly after ecdysis. The photo below may shed some light, or possibly create more confusion.
Also, to ease minds. I always intended on keeping her in my possesion and unpaired unless I could get a definitive ID. She's been living happily in her 10 gallon, where she'll remain until her eventual passing.
I have a similar colored cambridgei that has always been dark but in the last molt the pattern on her abdomen turned a greenish color .must be a hybrid . Its my fiercest t i wouldnt have it any other way